Acrylic Acid Esters Containing a N,N-Heterocyclic Ring

ABSTRACT

New acrylic acid esters and methacrylic acid esters are obtained by esterifying mono-hydroxyalkylated hydantoin compounds or dihydrouracil compounds with acrylic acid and/or methacrylic acid. The new acrylic acid esters and methacrylic acid esters are odourless substances which can be polymerised in a known manner, whereby polymers with a reactive 1 NH- grouping in the hydantoin ring or dihydrouracil ring are obtained, which can advantageously be processsed together with other resins.

Feb. 4, 1975 ACRYLIC ACID EST ERS CONTAINING A N,N-I-IETEROCYCLIC RING Inventors: Daniel Porret, BinningenyJurgen Habermeier, Pfeffingen, both of Switzerland Assignee: Ciba-Geigy Corporation, Ardsley,

Filed: July 9, 1973 Appl. No.: 377,698

Foreign Application Priority Data July 12, 1972 Switzerland 10424/72 U.S. Cl. 260/309.5, 260/260, 260/883 R Int. Cl C07d 49/32 Field of Search 260/3095 References Cited UNITED STATES PATENTS 4/1973 Habermeier et al 260/3095 Primary Examiner-Henry B. Jiles Assistant Examiner-C. M. S. .laisle Attorney, Agent, or Firm-Karl F. Jorda [57] ABSTRACT New acrylic acid esters and methacrylic acid esters are obtained by esterifying mono-hydroxyalkylated hydantoin compounds or dihydrouracil compounds with acrylic acid and/or methacrylic acid. The new acrylic acid esters and methacrylic acid esters are odourless substances which can be polymerised in a known manner, whereby polymers with a reactive 1 NH- grouping in the hydantoin ring or dihydrouracil ring are obtained, which can advantageously be processsed together with other resins.

10 Claims, No Drawings 1. ACRYLIC ACID ESTERS CONTAINING A N,N-HETEROCYCLIC RING The present invention relates to new acrylic acid esters and methacrylic acid esters of monohydroxyalkylated hydantoin compounds or dihydrouracil compounds, a process for their manufacture and the use of the new acrylic acid esters and methacrylic acid esters for the manufacture of polymers and copolymers.

Acrylic acid esters and methacrylic acid esters of aliphatic alcohols are known and a number of these compounds have already found a broad use for the manufacture of polymers, for example Plexiglas or acrylic resin lacquers. The acrylic acid esters of aliphatic alcohols, which industrially can be manufactured cheaply, are 'liquid and in most cases have a low vapour pressure and a pungent odour. Thus, appropriate safety precautions must be taken when working with these physiologically not entirely harmless acrylic acid esters. Furthermore, only linear polymers, which do not contain any reactive groups in the side chain, can be manufactured from these previously known monomers.

It has now been found that the use of certain acrylic acid esters and methacrylic acid esters, not previously described in the literature, of mono-hydroxyalkylated hydantoin compounds or dihydrouracil compounds is of particular interest for the manufacture of polymers or copolymers for certain applications. In contrast to the physiologically not harmless acrylic acid esters of aliphatic alcohols, the new acrylic acid esters are odourless crystalline substances which dissolve readily both in water and in most customary organic solvents and can be polymerised or copolymerised in the usual manner. The polymers obtained from the new acrylic acid esters possess lateral hydantoin rings or dihydrouracil rings with a free 1- NH grouping which is capable of further reaction, for example with phenolformaldehyde resins, melamine lacquers or epoxide resins.

The present invention thus relates to new acrylic acid esters of the formula H-N N-CH-CH-O-'EI-C=CH c I I (1) wherein Z represents a divalent radical of the formulae C y or 4 wherein X, and X each denote a hydrogen atom or an aliphatic, cycloaliphatic, araliphatic or aromatic hydrocarbon radical or together denote the tetramethylene or pentamethylene radical, X and X each denote a hydrogen atom or an aliphatic. cycloaliphatic, araliphatic or aromatic hydrocarbon radical, X and X,, each represent a hydrogen atom or an alkyl radical, and R, and R independently of one another each represent a hydrogen atom or the methyl group. and R represents a hydrogen atom, an alkyl group, an alkyl group interrupted by ether oxygen atoms. or the phenyl group. or R and R together denote the trimethylene or tetramethylene radical.

in the Formula I, preferably Z denotes the divalent radical of the formula wherein X, and X each represent a hydrogen atom or an alkyl radical with l 4 carbon atoms or together kz c=o H-N N ca ca 0a (II) wherein Z, R and R have the same meaning as in the Formula I, with acrylic acid and/or methacrylic acid in a manner which is in itself known, or trans-esterifying them with acrylic acid esters and/0r methacrylic acid esters in a manner which is in itself known.

In the direct esterification of the monohydroxy compounds ofthe Formula ll with acrylic acid and/or methacrylic acid, the reactants can be present either in approximately stoichiometric amounts or in a stoichiometric excess relative to the acrylic acid and/or methacrylic acid. The esterification reaction is advantageously carried out using an inert azeotropic agent. The reaction is as a rule acidcatalysed and carried out in the temperature range of 35 200C, preferably 60 C. For working up, the reaction solutions are washed until free of acid, concentrated, provided with stabilisers and then dried to constant weight in vacuo.

In the trans-esterification of the monohydroxy compounds of the Formula II with acrylic acid esters and/or methacrylic acid esters, acrylic acid esters or methacrylic acid esters of lower aliphatic alcohols are perferably used, preferentially in a stoichiometric excess. The trans-esterification reactions are acid-catalysed and are also carried out in the abovementioned temperature range. The lower aliphatic alcohol produced in this reaction is continuously distilled from the hatch.

The excess monoacrylic acid ester or monomethacrylic acid ester is also removed from the reaction mixture by distillation. The crude product is then dissolved in an organic inert solvent, for example benzene, and worked up analogously to the reaction solutions obtained by esterification.

The monohydroxy compounds of the Formula ll are known compounds and can be manufactured according to the process described in US. Pat. No. 3,629,263. by adding onto 1 mol ofa N-heterocyclic compound ofthe formula wherein Z has the same meaning as in the Formula I, 1 mol of a monoepoxide of the formula R CH (EH-R wherein R and R have the same meaning as in the Formula I, in the presence of a suitable catalyst.

As suitable representatives of monoepoxides of the Formula IV there may be mentioned: ethene oxide, propene oxide, n-butene oxide, 1,2-cyclopentene oxide or 1,2-cyclohexene oxide, styrene oxide and glycidyl alkyl ethers, such as butyl-, amyl-, octylor dodecenylglycid. 2'

A preferred class of compounds amongst N- heterocyclic monohydroxy compounds, which are employed as starting substances, corresponds to the formula H N cu onon (III) phatic ployed as starting substances, corresponds to the formula wherein X X X X R and R have the same meaning as in the Formula I. As individual compounds there may be mentioned: 3-(2'-hydroxyethyl)-5,5-dimethyl- 6-isopropyl-5,6-dihydrouracil, 3-(2-hydroxy-npropyl)-5,5-dimethyl-6-isopr0pyl-5,6-dihydrouracil and 3-(2-hydroxy-2-phenyl)-5,5-dimethyl-6-isopropyl-5,5-dihydrouracil.

The new acrylic acid esters of the Formula I are crystalline substances which melt in the range of 40l 20C. The new acrylic acid esters, which are soluble in water and in numerous organic solvents, can easily be prepared in a pure form by recrystallisation, and this increases their storage stability and permits dispensing with the addition of customary inhibitors.

The acrylic acid esters of the Formula l manufactured according to the invention are valuable compounds which can be polymerised by themselves or together with other polymerisable monomers, whilst being shaped or as sheet-like structures.

Possible monomers which can be added to the new acrylic acid esters of the Formula I are both com pounds of the acrylic acid series, such as esters of acrylic acid or methacrylic acid and alcohols or phenols, for example methyl acrylate, butyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile and ethylene glycol dimethacrylate, and other reactive, olefinically unsaturated monomers, such as, for example, styrene, divinylbenzene and vinyl acetate.

Preferably, the customary free radical-forming catalysts are used for the polymerisation or copolymerisation; there may be mentioned hydrazinederivatives, for example hydrazine hydrochloride, organo-metallic compounds, such as lead tetraethyl, and especially aliazo compounds, such as a, a-azoisobutyrodinitile, and organic peroxides or per-salts, such as, for example, peracetic acid, acetyl peroxide, chloroacetyl peroxide, trichloroacetyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, benzoylacetyl peroxide, propionyl peroxide, fluorochloropropionyl peroxide, lauroyl peroxide, cumene hydroperoxide, cyclohexanone hydroperoxide, tert.butyl hydroperoxide, di-tert.-butyl peroxide, di-tert.-amyl peroxide and pmenthane hydroperoxide; also inorganic peroxide compounds, such as sodium peroxide, alkali metal percarbonates, alkali metal persulphates or alkali metal perborates and especially hydrogen peroxide, which can advantageously replace the more expensive benzoyl peroxide. The amount added depends, in a known manner, on the desired course of the reaction or the desired properties of the polymer; advantageously, about 0.05 to 10 per cent by weight of the catalyst, relative to the total weight of the polyacrylate mixture or polyacrylate-monomer mixture are employed, the total amount of the catalyst being added either at the beginning or in portions over the course of the polymerisation.

1n certain cases, cationic or anionic catalysts can also be used.

The acrylic acid esters manufactured according to the invention, or their mixture with other polymerisable monomers, can be used in surface protection. in compression moulding compositions. as casting resins and the like.

Hence, the present application also relates to curable mixtures which are suitable for the manufacture of shaped articles, including sheet-like structures; and which contain the acrylic acid esters according to the invention, optionally together with other polymerisable monomers, and the polymerisation catalysts customary for the polymerisation curing.

The polymerisable mixtures suitable for the manufacture of coatings and compression moulding compositions can additionally also contain plasticisers, fillers and preferably pigments, for example titanium dioxide.

The homopolymers or copolymers obtained from the new monomeric acrylic acid esters of the Formula 1 ac cording to known polymerisation processes are hard, high-melting substances which are preferably used in surface protection agents or in compression moulding compositions.

Hence, the present invention also relates to new homopolymers or copolymers having the recurring structural unit of the formula wherein Z, R,, R and R have the same meaning as in the Formula 1 and n is a number greater than 4.

Preferably, in the Formula Vll, Z denotes the diva lent radical of the formula wherein X and X each denote a hydrogen atom or an alkyl radical with l 4 carbon atoms or together denote the tetramethylene or pentamethylene radical, R, and R independently of one another each represent a hydrogen atom or the methyl group and R denotes a hydrogen atom or the methyl or phenyl group, or

wherein R and R together denote the trimethylene or tetramethylene radical, and n denotes a number having a value of 5 250.

The homopolymers and copolymers having the structural characteristic of the Formula Vll contain lateral N-heterocyclic rings with a free-l-NH- grouping, which is capable of further reaction, for example with phenol-formaldehyde resins, melamine resins or epoxide resins. The reactive linear polymers according to the Formula Vll are therefore suitable. by themselves or preferably in combination with compounds which possess several functional groups capable of reaction with the reactive l-NH- grouping. for the manufacture of lacquers or coatings. films, compression moulding compositions and the like.

In the examples which follow. unless otherwise stated, parts denote parts by weight and percentages denote percentages by weight.

EXAMPLE 1 A mixture of 1,033.2 g of 3-(2'-hydroxyethyl)-5.5- dimethylhydantoin (6 mols), 775 g of methacrylic acid (9 mols; corresponding to 50% excess of methacrylic acid), 3 litres of toluene, 20 ml of 50% strength sulphuric acid, 0.45 g of phenothiazine and 3 g of triphenylphosphite is brought to 103C internal temperature whilst stirring, at 160C bath temperature, in a stirred flask of 6 litres capacity provided with a thermometer, stirrer, dropping funnel, water separator with reflux condenser and receiver. 1n the course thereof, a vigorous circulatory distillation commences and the progress of the reaction is ascertained in the water separator from the amount of water which has separated out. After 1 hour, 20 ml of50% strength sulphuric acid are again added by means ofa dropping funnel. The internal temperature now rises to l 13C in the course of the reaction. After a total of 13 hours, ml of water are present in the receiver (theory: 128 ml) and the reaction is terminated by cooling to room temperature.

To isolate the desired methacrylate, the reaction mixture obtained is twice extracted by shaking with 500 ml of an aqueous solution which contains 10% of ammonia and 5% of ammonium sulphate.

Thereafter, the following stabiliser mixture is added to the organic phase: 0.5 g of hydroquinone, 0.14 g of pyrocatechol, 0.04 g of copper naphthenate (87: strength) and 0.05 g of NaNO in 0.15 g of H 0.

The organic phase is now completely concentrated at 55C/l5 mm Hg and dried to constant weight. 1,123.3 g of a beige-coloured crystalline material (84% of theory) are obtained.

The new methacrylate can be purified, for example, by recrystallisation from a tetrahydrofuran/hexane (1:1) solvent mixture or from cyclohexane. A 200 g sample recrystallised from cyclohexane yields 138 g of colourless crystals (without working up the mother liquor) melting at 809C (Mettler FP 51; speed of heating: 1C/minute).

The elementary analysis gives the following values:

Found Calculated 7 Both micro-hydrogenation (in glacial acetic acid, with PtO at 22C) and titrimetric determination of the double bond according to D. W. Beesing et a1. (Analytical Chemistry 21 (9), 1073 (1949) and D. Miiller (Zeitschriftfiir analytische Chemie 18, 135 137 Fmmd: Calcumed (1961)) show that the calculated amount of methacryl- L130 9; N M38 N ate groups is present. The IR (infra-red) spectrum and 6.30 /l H 6.24 '1; H the H-NMR (proton-magnetic resonance) spectrum, which shows the following signals, are in agreement The H-NMR spectrum sgrees with the following with the formula shownbelow: L structure:

CH '5 1 1 t c 5 6H .59 slng e 5H 6 1.87 singlet: H cc=c 4H 6 5.7-5.85 triplet N-CH CH 6 4.'24.4 triplet 1 ah) 685's lt' lt Hcc mu 1p e i a 6.05 2

6 6.50 singlet /N, -H

l l 0 H-N N-Cl-1 CH -O-EI (I; Z c .011 n 3 0 EXAMPLE 2 40 H C CH The following mixture is brought to 82C (bath temperature 150C) whilst stirring in an apparatus similar 6 C v to that described in Example 1: 172.2 g of 3-(2'- i I 2 hydroxyethyl)-5,5-dimethylhydantoin (1 mol), 108.2 g N m of acrylic acid (1.5 mols), 600 ml of benzene, 12 g of C 2 0 CF 2 p-toluenesulphonic acid, 40 g of Acid lon Exchanger l, c (commercially obtainable from Messrs. Merck under I this name), 0.08 g of phenothiazine and 0.5 g of triphenylphosphite. W n

EXAMPLE 3 As soon as the mixture has reached the temperature indicated above, the elimination of water from the system starts immediately. After about 30 hours, the reaction is complete. The mixture is cooled to 25C and filtered, and working up, isolation and stabilisation are then carried out in accordance with Example 1.

133 g (59% of theory) of a light yellow crystalline mass are obtained, of which the content of acrylate groups corresponds, according to titration, to 95% of the theoretical value, whilst micro-hydrogenation indicates a 100% acrylate content.

The purity can be estimated to be approx. 96% from the H-NMR spectrum, from the ratio of the integral of 2. 195 g of a clear, light yellow, viscous liquid, which crystallises throughout after a few hours, are obtained. The content of acrylate groups is 97.6% of theory, according to titration; micro-hydrogenation indicates a value of of theory and the H-NMR spectrum shows a purity of about 97% of theory.

For purification, a sample is recrystallised from a solvent mixture consisting of tetrahydrofurune/hexane (1:1) in the ratio of 1:1. A colourless crystal powder is obtained, which melts at 91.2C (Mettler FP 51", using a speed of heating of 1C/minute) and of which the acrylate group content is determined by titration to be 4.08 equivalents/kg (corresponding to 98.3% of theory). The new acrylate corresponds to the following formula:

The reaction product obtained is worked up accord ing to the procedure described in Example 1 and 253.6 g of a crude product which is coloured pale red-brown and is solid at room temperature (83. 91 oftheory) are obtained, wherein the content of acrylic ester groups corresponds to 69.5% of theory. The new acrylate accordingly corresponds to the following structure:

hydroxypropyl)-5,5-dimethylhydantoin mols) are reacted with 645.8 g of-mcthacrylic acid (7.5 mols) in 3 litres of toluene. The reaction is catalysed with 37 ml of 50% strength sulphuric acid which is continuously added dropwise to the reaction mixture over the course of 5 hours. To prevent premature polymerisations. 0.4

g of phenothiazine and 2.5 g of triphenolphosphite are 30 added to the reaction mixture.

The mixture is heated to 106C whilst stirring and the separation of water then commences 175C bath temperature).

After 18 hours, 1 ml of water have separated and the reaction is terminated by cooling to C. Working up takes place according to Example 1 and 938 g (73.5% of theory) of colourless crystals are produced. These can be purified by recrystallising from a tetrahydrofurane/hexanc (1:1) solvent mixture in the ratio of 112.5. The colourless powder thus obtained melts at 103.3"C and consists. according to the H-NMR spectrum, of

O H-N )i-ca ca-o-il c= H H3 EXAMPLE 5 3-(2'-phenyl-2'-hydroxyethyl)-5,5- 5

no on o 3 c--c. l l o 11-N N-CH2-CH-0-C-CH=CH EXAMPLE 6 The acrylic acid ester of 3(2-hydroxycyclohexyl)- 5,5-dimethylhydantoin is manufactured by reacting the following reaction mixture in accordance with the conditions described in Example 5: g of 3-(2- hydroxycyclohexyl)-5,5-dimethylhydantoin (0.155 mol), 16.74 g ofacrylic acid (0.232 mol), 95 m1 oftolucne. 0.5 m1 of H 50, strength), 0.012 g of phenothiazine and 0.08 g of triphenylphosphite.

After working up the reaction product according to the procedure of Example 1. 35.0 g (80.6% of theory) of a light brown, highly viscous, partially crystalline substance containing 62% of theory of acrylate groups are obtained.

Remnants ofunreacted starting material are removed by dissolving in toluene. After concentration and drying, a light yellow substance which crystallises at room temperature is obtained, the purity of which is found to be 94-9557: by titrimetric determination of the acrylate double bonds.

Elementary analysis shows the following values:

Found Calculated:

60.0 92 C 59.99 72 C 7.4 H 7.19 '71 H Accordingly, the new acrylate corresponds to the following structure:

EXAMPLE 7 The methacrylic acid ester of 3-(2-hydroxy-npropyl)-5,5-tetramethylenehydantoin is manufactured by reacting the following reaction mixture under the reaction conditions described in Example 62.2 g of 3-(2'-hydroxy-n-propyl)-5,S-tetramethylenehydantoin (0.31 mol), 48.9 g of methacrylic acid (0.46 moi), 2.5 g of H 80 (50% strength), 0.028 g of phenothiazine and 0.18 g of triphenylphosphite.

After working up according to Example 1, 40.8 g (48% of theory) of a light yellow, crystalline mass are obtained, of which the methacrylic acid ester content is 84.6% of theory.

The substance can be purified by recrystallisation from toluene. Colourless, fine crystals are obtained, the melting point of which is l15.lC (Mettler FP 51", speed of heating: 2C/per minute). The titration of methacrylate groups indicates a content of 100% of theory; equally, microhydrogenation in glacial acetic acid at 22C, using PtO shows that the substance is 100% pure with reference to C=C double bonds.

Elementary analysis shows the following values:

Accordingly, the substance accords with the following structure:

phenylethyl)-5 ,5-pentamethylenehydantoin is man ufactured analogously to Example 7 by reaction of the following reaction mixture: 153 g of 3-(2'-hydroxy-2' phenylethyl)-5,S-pentamethylenehydantoin (0.53

mol), 57.3 g ofacrylic acid (0.795 mol), 350 ml of toluene, 1.8 ml of H SO, (50% strength), 0.035 g of phenothiazine and 0.265 g of triphenylphosphite.

After working up according to Example 7, 176.3 g of a brown, high viscous crude product are obtained, of which the content of acrylate groups is63.87% of theory. The pure acrylate corresponds to the following structure:

I ll CH CH-O-CCH=0H C ll 0 EXAMPLE9 The acrylic acid ester of 3-(2-hydroxy-2'- ll. Polymerisation of the acrylic ester derivatives EXAMPLE 1 24 g of the methacrylate manufactured according to Example 1 (0.1 mol) are dissolved in 100 ml of water at C, whilst stirring. A mixture of0.l g of potassium persulphate and 2.5 g of isopropanol is added to the colourless, clear solution. The temperature is raised to C, whereupon the solution becomes turbid and a precipitate slowly forms. The mixture is stirred for a further 4 hours at 80C and is then cooled to 30C. The precipitate is dried by suction-filtration, rinsed with a large amount of water and dried to constant weight at 15 mm Hg over P 0 23 g (95.8% of theory) of a colourless powder melting at 267C are obtained.

Elementary analysis shows:

Found: Calculated:

11.4%N 11.7%N 6.8%H 6.7%H

The molecular weight determined by vapour pressure osmometry shows a numerical average molecular weight of 16,650 (i 10% The polymer has essentially the following structure:

Use example 7.0 g of the acrylate manufactured according to Example 9 are mixed with 70 mg of benzoyl peroxide and the mixture is heated to 120C for 1 hour. In the course thereof, the viscous substance changes to a product which is glassy at room temperature and has a glass transition temperature of 80C (Kofler bench). This polymer is treated with 4 g of a 75% strength solution of a melamine-formaldehyde-n-butylether resin in nbutyl alcohol and 8.5 g of ethylglycol acetate. Further, 0.5 ml ofa strength solution of p-toluenesulphonic acid in ethanol is added to the homogeneous solution. This clear lacquer is applied to degreased aluminium sheets and cured for 40 minutes at 180C. This yields scratch-resistant, hard films which are also resistant to toluene. alcohol and acetone.

The melamine-formaldehyde-n-butyl-ether resin used is a condensation product of l mol melamine, 5.5 mols of formaldehyde and 3.5 mols of n-butyl alcohol. It is commercially available as a 75% strength solution in butyl alcohol.

We claim:

1. Acrylic acid esters of the formula c--c--o 2 l an N-CH-CH-O-CC=CH approx 69 wherein X and X each represent a hydrogen atom or an alkyl radical with l-4 carbon atoms or together represent the tetramethylene or pentamethylene radical, R and R independently of one another each represent a hydrogen atom or the methyl group and R represents a hydrogen atom or the methyl or phenyl group, or wherein R and R together represents the trimethylene or tetramethylene radical.

2. A compound as claimed in claim I. which is 3- (methacryloyloxyethyl)-5.S-dimethylhydantoin.

3. A compound as claimed in claim 1, which is 3- (acryloyloxyethyl)-5,5-dimethylhydantoiri. 

1. ACRYLIC ACID ESTERS OF THE FORMULA
 2. A compound as claimed in claim 1, which is 3-(methacryloyloxyethyl)-5,5-dimethylhydantoin.
 3. A compound as claimed in claim 1, which is 3-(acryloyloxyethyl)-5,5-dimethylhydantoin.
 4. A compound as claimed in claim 1, which is 3-(acryloyloxyisopropyl)-5,5-dimethylhydantoin.
 5. A compound as claimed in claim 1, which is 3-(methacryloyloxyisopropyl)-5,5-dimethylhydantoin.
 6. A compound as claimed in claim 1, which is 3-(acryloyloxy-2''-phenylethyl)-5,5-dimethylhydantoin.
 7. A compound as claimed in claim 1, which is 3-(2''-acryloyloxycyclohexyl)-5,5-dimethylhydantoin.
 8. A compound as claimed in claim 1, which is 3-(methacryloxyloxyisopropyl)-5,5-tetramethylenehydantoin.
 9. A compound as claimed in claim 1, which is 3-(acryloyloxy-2''-phenylethyl)-5,5-pentamethylenehydantoin.
 10. A compound as claimed in claim 1, which is 3-(acryloxyloxy-2''-phenylethyl)-5-isopropylhydantoin. 